


Demonic

by Fandom_Stuff



Series: Suptober20 [3]
Category: Supernatural
Genre: Demons, Mark of Cain Dean, demonic
Language: English
Status: Completed
Published: 2020-10-03
Updated: 2020-10-03
Packaged: 2021-03-08 02:27:51
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 875
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26798086
Author URL: https://archiveofourown.org/users/Fandom_Stuff/pseuds/Fandom_Stuff
Summary: This ficlet was written for the prompt 'demonic' as a part of Suptober20 onTumblr
Series: Suptober20 [3]
Series URL: https://archiveofourown.org/series/1953955
Kudos: 4





	Demonic

Castiel had worried about Dean the second he took on the mark of Cain, but his worry had continued to increase with every angry outburst Dean had. After Dean had slaughtered Randy and everyone else in that house, he knew that it was only a matter of time before the mark completely consumed him and he lost any form of control he might have had. 

But he hadn’t known how close Dean was to breaking, until he’d caught him surrounded by the bodies of the Styne family. The anger he’d seen in Dean’s eyes, the hatred, the disgust, it had buried itself deep in Castiel’s core. He would never forget the look on Dean’s face as he lashed out, as he slammed Castiel into the table, over and over again, or the emptiness in his eyes as he reared up to plunge the angel blade into his chest, or the feeling of blood clogging his throat as he gasped out a plea for Dean to spare him, the only strength left in his body aiding his hand to grasp at Dean’s wrist. 

He felt Dean’s heartbeat pulsing through his fingers, the rapid staccato of it showed just how angry Dean was, and yet Castiel could also feel his fear, the hesitation in his body as he looked down at Castiel below him, bloodied and broken, at his mercy. 

When the blade pierced the book beside Castiel’s head, and Dean stormed off, Castiel stayed on the bunker floor for a long time. Gradually, he healed his wounds, and began to clean up the mess the Styne’s had left behind. His mind raced with thoughts of the person Dean was becoming, how there was hardly anything left of the man Dean was before the mark. But there was  _ something _ , because Dean hadn’t killed him, there had been humanity in Dean’s eyes; he wasn’t gone yet. 

But Castiel didn’t know how to save him. 

The mark wasn’t coming off. There was nothing he could do but hope that Dean could fight it and remember who he was. 

Of course, Dean couldn’t fight forever, and when Metatron killed him, that’s when Castiel knew that it was only going to go downhill from here. Dean became a demon, the very thing that he hunted. Dean had abandoned them, walked off with  _ Crowley _ , but Sam was adamant to find him, and find him he did.

Castiel couldn’t quite believe just who Dean had turned into. The horror of finding the same man who used to do anything to save his loved ones, attempting to kill his brother, was not something Castiel ever thought he’d watch. But Dean wasn’t Dean anymore, he was corrupted by the mark, every good part of him was buried deep inside his twisted soul. 

Castiel could feel the power of the mark when he embraced Dean, when he told him it was over. The anger that radiated from Dean’s body when he struggled against Castiel’s arms was so powerful, that Castiel wondered how Dean hadn’t been ripped apart. 

Hearing Dean’s screams as Sam pushed needle after needle into Dean’s skin made Castiel’s heart clench in his chest. Pain was never something Castiel ever wanted Dean to be in. When he’d fought his way through Hell, he had followed the sound of Dean’s suffering, he’d been drawn to the shattered soul of the righteous man, and the more he fought off demons and hellhounds, the closer he got to the broken boy. All he wanted to do was stop his pain. He tried to reach for him before he could pick up a blade of his own, but alas, he had been too late. 

Dean wielded Alistair’s tools like it was his purpose, he cut into soul after soul with an empty expression and a set to his jaw. That was where Castiel had first glimpsed the man that would bear the mark of Cain, but the difference between the person Alistair had welded Dean into, and the man whose screams were filling the bunker right now, was that the man in Hell, the man who had picked up a blade and dished out the pain instead of bearing it, felt remorse. In Hell, Dean’s soul was never going to darken into the black smoke of a demon. He was too pure, too righteous, his soul would continue to shine even in the darkest pits of Hell. But when Dean took on that mark, that was when Castiel first saw the cloud of gray bearing down on Dean’s perfect soul, that was how he knew that this mark would be nothing but bad news. 

As Sam pushed another needle into Dean’s skin, Castiel watched as the haze around Dean’s soul finally cleared, and the black of Dean’s eyes returned to their forest green. Dean blinked at them, confusion on his face, fear taking ahold of him as everything he’d done came rushing back. 

He still had the mark, but there was just a little less anger in his eyes and a little more humanity. It was in that moment, that Castiel vowed to himself, that he would do whatever it took to free Dean of this curse. He would not live to watch Dean become a demon again. 


End file.
